Obstacle alert device

ABSTRACT

An obstacle alert device notifies a driver of the presence of an obstacle approaching a vehicle without making it difficult to see a state of the periphery of the vehicle. The apparatus includes: a captured image obtainment unit that obtains a captured image of a scene of the periphery of the vehicle; a target captured image generation unit that generates a target captured image based on the captured image; an object presence determination unit that determines whether or not an object is present in an outside region that is on an outer side of the target captured image; a movement direction determination unit that determines a movement direction of the object in the outside region; and a notification image output unit that, in the case where the movement direction determination unit has determined that the object in the outside region is moving toward the center of the target captured image, sequentially displays a plurality of indicators, that appear for a set amount of time and then disappear, in different locations of the target captured image, starting with the side having the outside region in which the object is present and moving toward the center of the target captured image, and repeats this display while displaying the plurality of indicators in positions where the indicators partially overlap with each other, with the indicator displayed later being displayed over the indicator displayed immediately previous thereto at the areas where the indicators overlap.

TECHNICAL FIELD

The present invention relates to obstacle alert devices that alertoccupants in a vehicle of the presence of nearby obstacles.

BACKGROUND ART

A vehicle's periphery contains blind spots that cannot be seen from adriver's position, and it is thus necessary for drivers to pay carefulattention to the vehicle's periphery when driving the vehicle. Manydrivers feel they are unskilled at parking vehicles in general, and thusexperience significant emotional stress particularly when backing avehicle into a parking spot. In light of this, techniques that monitor avehicle's periphery for obstacles have been used for some time (forexample, see Patent Documents 1 and 2).

Patent Document 1 discloses an obstacle alert device for a vehicle,configured of a laterally-moving obstacle detection means, a lateralmovement direction detection means, and a lateral movement informationpresenting means. The laterally-moving obstacle detection means detectsan obstacle, in front of the vehicle, moving in a direction that crossesthe direction in which the vehicle is moving. The lateral movementdirection detection means detects the direction of the lateral movementof the obstacle detected by the laterally-moving obstacle detectionmeans. The lateral movement information presenting means presents, to adriver, information regarding the direction of the lateral movement ofthe obstacle detected by the lateral movement direction detection means.Here, the lateral movement information presenting means displays anarrow indicating the direction of the lateral movement detected by thelateral movement direction detection means in a display unit.

Patent Document 2 discloses a vehicle periphery monitoring deviceconfigured of an imaging means, an obstacle detecting means, and adisplay means. The imaging means captures an image of the vehicle'speriphery, including part of the vehicle itself. The obstacle detectingmeans detects an obstacle located in the vehicle's periphery andcalculates a distance between the detected obstacle and the vehicle. Thedisplay means displays the image captured by the imaging means and anobstacle display image indicating the distance calculated by theobstacle detecting means in a single screen.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: JP H11-115660A

Patent Document 2: JP 2009-217740A

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

By detecting an obstacle in the vehicle's periphery and displayinginformation (an arrow or the like) indicating that obstacle in a screen,techniques such as those disclosed in Patent Document 1 and PatentDocument 2 enable a driver to be aware of the presence of obstacles inthe vehicle's periphery. However, displays (display means) mounted invehicles do not have large screens. As such, when an arrow or the likeis displayed in an image indicating the state of the vehicle's peripheryin a display, it may be difficult to see the state of the vehicle'speriphery, the driver may be unable to notice the obstacle, and so on.

Having been achieved in light of the aforementioned problem, it is anobject of the present invention to provide an obstacle alert devicecapable of notifying a driver of an obstacle approaching a vehiclewithout making it difficult to see the state of the vehicle's periphery.

Means for Solving Problem

To achieve this object, a characteristic configuration of an obstaclealert device according to the present invention includes: a capturedimage obtainment unit that obtains a captured image of a scene of theperiphery of a vehicle; a target captured image generation unit thatgenerates a target captured image based on the captured image; an objectpresence determination unit that determines whether or not an object ispresent in an outside region that is on an outer side of the targetcaptured image; a movement direction determination unit that determinesa movement direction of the object in the outside region; and anotification image output unit that, in the case where the movementdirection determination unit has determined that the object in theoutside region is moving toward the center of the target captured image,sequentially displays a plurality of indicators, that appear for a setamount of time and then disappear, in different locations of the targetcaptured image, starting with the side having the outside region inwhich the object is present and moving toward the center of the targetcaptured image, and repeats this display while displaying the pluralityof indicators in positions where the indicators partially overlap witheach other, with the indicator displayed later being displayed over theindicator displayed immediately previous thereto at the areas where theindicators overlap.

According to this characteristic configuration, even if the object hasnot yet appeared in a screen of a display device (for example, amonitor) provided in the vehicle, a driver of the vehicle can benotified of the presence and direction of the object approaching thevehicle at the point in time when the object approaching the vehicle hasentered a captured range, while at the same time displaying the state ofthe periphery of the vehicle. Accordingly, the driver will not fail tosee the object approaching the vehicle even in the case where thedisplay device has a small screen. Furthermore, because the indicator isdisplayed in an end area of the screen, it is not difficult for thedriver to see the state of the periphery of the vehicle. Accordingly,the driver can be notified of the presence of an obstacle (the object)approaching the vehicle without the state of the periphery of thevehicle being difficult to see. Furthermore, the indicator can bedisplayed so as to move toward the center of the screen. Accordingly, itis easier for the driver to instinctively recognize that the obstacle isapproaching.

Here, it is preferable for the indicator displayed later to be displayedat a larger size than the indicator displayed immediately previousthereto.

According to this configuration, the indicator moving toward the centerof the screen can be displayed in a more visual manner. Accordingly, itis easier for the driver to effectively recognize that the obstacle isapproaching.

Here, it is preferable for the indicator displayed later to be displayedat a lower level of transparency than the indicator displayedimmediately previous thereto.

According to this configuration, the indicator moving toward the centerof the screen can be displayed in a more visual manner. Accordingly, itis easier for the driver to effectively recognize that the obstacle isapproaching. Furthermore, the scene displayed at the end area of thescreen is not hidden, and thus the obstacle can be recognizedappropriately even in the case where the obstacle has jumped outsuddenly.

Here, it is preferable for the indicator to be configured in an arrowshape whose point protrudes toward the center of the target capturedimage.

According to this configuration, the movement direction of the obstaclematches the direction in which the arrow protrudes, and thus the drivercan instinctively recognize the movement direction of the obstacle.

Here, it is preferable for the notification image output unit to beconfigured to stop the output of the indicator in the case where theobject has advanced into a region corresponding to the target capturedimage.

According to this configuration, the display of the indicator can bestopped at the point in time when the object has appeared in the screenof the display device (that is, the display image), and thus the objectwill not be hidden by the indicator. Accordingly, the driver canappropriately view the object that has approached the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically illustrating the configurationof an obstacle alert device.

FIG. 2 is a diagram illustrating an example of processing performed bythe obstacle alert device.

FIG. 3 is a diagram illustrating an example of a synthesized image.

FIG. 4 is a diagram illustrating an example of a synthesized image.

FIG. 5 is a diagram schematically illustrating processing performed bythe obstacle alert device.

FIG. 6 is a diagram illustrating a synthesized image according toanother embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail. An obstacle alert device 100 according to the present inventionincludes functionality for notifying a driver that an object isapproaching a vehicle in such a case where an object is approaching avehicle. This will be described hereinafter using the drawings.

FIG. 1 is a block diagram schematically illustrating the configurationof the obstacle alert device 100. As shown in FIG. 1, the obstacle alertdevice 100 is configured of functional units including a captured imageobtainment unit 11, a target captured image generation unit 12, anoutside region generation unit 13, an object presence determination unit14, a movement direction determination unit 15, a notification imageoutput unit 16, a notification image storage unit 17, a synthesizedimage generation unit 18, a mask region setting unit 19, a mask regionemphasis display unit 20, an action image output unit 30, and an actionimage storage unit 31. The functional units are constructed of hardware,software, or both, and function with a CPU serving as a core member, soas to perform various processes for notifying a driver of a vehicle 1that an object 7 is approaching.

The captured image obtainment unit 11 obtains a captured image G showinga scene of the periphery of the vehicle 1. The vehicle 1 is providedwith a camera 5. The camera 5 according to the present embodiment isconfigured of a digital camera that includes an image sensor such as aCCD (charge coupled device) or a CIS (CMOS image sensor) and thatoutputs captured data as moving picture data. As shown in FIG. 2( a),the camera 5 is installed near the license plate on an outer rear areaof the vehicle 1, near an emblem on the outer rear area of the vehicle1, or the like, facing rearward from the vehicle 1 at a slight downwardangle. The camera 5 is configured having a wide-angle lens (not shown).As such, the scene of the periphery of the vehicle 1 can be capturedacross an approximately 180-degree range behind the vehicle 1. Thiscaptured range is indicated as a “wide view angle” in FIG. 2( a). Thecamera 5 has the capability to output a real-time moving picture as thecaptured image G. The captured image G is transferred to the capturedimage obtainment unit 11.

FIG. 2( b) illustrates an example of the captured image G. The totalwidth in FIG. 2( b) corresponds to the wide view angle of FIG. 2( a). Animage inversion process is carried out on the captured image G so thatthe object 7, which as shown in FIG. 2( a) is located on the left sidewhen viewed from the back of the vehicle 1, is displayed on the rightside in the captured image G, as shown in FIG. 2( b). This makes iteasier for the driver of the vehicle 1 to visually grasp whether theobject 7 in the captured image G is on the left side or the right sideof the vehicle 1 when the scene to the rear of the vehicle 1 isdisplayed in a monitor 50.

Returning to FIG. 1, the target captured image generation unit 12generates a target captured image based on the captured image G. In thepresent embodiment, the captured range of the captured image Gcorresponds to the wide view angle. Accordingly, the target capturedimage generation unit 12 generates a narrow view region N, whichcorresponds to a central area of the captured image G, as the targetcaptured image. The captured image G is transferred from the capturedimage obtainment unit 11 mentioned earlier. In the present embodiment,the target captured image corresponds to the central area of thecaptured image G in the horizontal direction, as shown in FIG. 2( b). Itis preferable for the narrow view region N to be a region covering, forexample, approximately 120 to 130 degrees to the rear of the vehicle 1,as indicated by “narrow view angle” in FIG. 1( a). Meanwhile, the narrowview region N is close to a possible range of travel when the vehicle 1is traveling in reverse and as such is a region in the captured image Gthat should be given particular attention; hence the region is labeledthe “target captured image”. The target captured image corresponds to adisplay image displayed in the monitor 50, which will be mentioned later(see FIG. 2( c)). Note that the present embodiment is described assumingthat the “target captured image” is an image of the “narrow viewregion”.

The outside region generation unit 13 generates an outside region O, onthe outside of the target captured image. That is, the outside region Ois generated corresponding to the areas of the captured image G that areoutside the narrow view region N. As described above, the narrow viewregion N is generated by the target captured image generation unit 12,in the central area of the captured image G in the horizontal direction.The outside region generation unit 13 generates the outside region O asshown in FIG. 2( b), on the outside of the narrow view region N in thehorizontal direction. The outside region O generated by the outsideregion generation unit 13 is transferred to the object presencedetermination unit 14, described below.

The object presence determination unit 14 determines whether or not theobject 7 is present in the outside region O. The outside region O istransferred from the outside region generation unit 13. Determiningwhether or not the object 7 is present can be performed using a knownimage recognition process, such as pattern matching, for example. Ofcourse, whether or not the object 7 is present in the outside region Ocan be determined through a process aside from pattern matching. Aresult of the determination performed by the object presencedetermination unit 14 is transferred to the movement directiondetermination unit 15, described below.

The movement direction determination unit 15 determines a movementdirection of the object 7 in the outside region O. This movementdirection determination is performed in the case where the objectpresence determination unit 14 has determined that the object 7 ispresent in the outside region O. More specifically, in the presentembodiment, the movement direction determination unit 15 determineswhether or not the object 7 in the outside region O is moving toward thenarrow view region N. “Moving toward the narrow view region N” refers tomovement in a direction from an area outside the immediate rear of thevehicle 1 in the width direction thereof, toward an area immediatelybehind the vehicle 1. This determination can be performed by, forexample, comparing the position of the object 7 in the current capturedimage G with the position of the object 7 in a captured image G from apredetermined amount of time previous, or by using a known method suchas using an optical flow. A result of the movement directiondetermination is transferred to the notification image output unit 16,described below.

In the case where the movement direction determination unit 15 hasdetermined that the object 7 in the outside region O is moving towardthe center of the target captured image, the notification image outputunit 16 sequentially displays an indicator S, that appears for a setamount of time and then disappears, in different locations of the targetcaptured image, starting with the side having the outside region O inwhich the object 7 is present and moving toward the center, and repeatsthis display. In the present embodiment, the target captured imagecorresponds to an image of the narrow view region N. Accordingly, in thecase where the object 7 in the outside region O is moving toward thenarrow view region N of the vehicle 1, the notification image outputunit 16 sequentially displays the indicator S, that appears for a setamount of time and then disappears, in different locations of the narrowview region N, starting with the side having the outside region O inwhich the object 7 is present and moving toward the center, and repeatsthis display. Whether or not the object 7 in the outside region O ismoving toward the narrow view region N of the vehicle 1 is determined bythe movement direction determination unit 15, described above. Thenarrow view region N on the side of the outside region O in which theobject 7 is present corresponds to the left side of the narrow viewregion N in the case where the object 7 is in the outside region O onthe left side. Likewise, this corresponds to the right side of thenarrow view region N in the case where the object 7 is in the outsideregion O on the right side.

The “indicator S that appears for a set amount of time and thendisappears” refers to a state in which the indicator S is notcontinually displayed, but rather in which the indicator S is blinking.In the present embodiment, when the indicator S is displayed, removed,and then once again displayed, the indicator S is displayed in adifferent position. Accordingly, the indicator S moves between twopredetermined positions in the screen while blinking. The notificationimage output unit 16 repeats the movement of the indicator S whilecausing the indicator S to blink.

The indicator S will now be described. The indicator S according to thepresent embodiment is shaped as an arrow whose point protrudes towardthe center of the target captured image (the narrow view region N). Asindicated in FIG. 2( d), the indicator S is stored in the notificationimage storage unit 17. FIG. 2( c) indicates an image displayed in themonitor 50 of the vehicle 1 in the case of the captured image G shown inFIG. 2( b), or in other words, in the case where the object 7 is presentin the outside region O on the right side. As shown in FIG. 2( c), aplurality of indicators S are displayed in the monitor 50 in the presentembodiment. In this case, the plurality of indicators S are displayed inpositions where respective indicators S partially overlap. In thepresent embodiment, “partially overlapping” refers to a part of one ofthe indicators S on the protruding side of the arrow shape overlappingwith a part of another of the indicators S on the non-protruding side ofthe arrow shape. Furthermore, in the case where there are a plurality ofindicators S, the area of overlap between one of the indicators S andthe indicator S displayed immediately previous thereto is configured sothat the indicator S displayed later is displayed over the indicator Sdisplayed immediately previous thereto. In other words, the indicator Sdisplayed later is positioned in a layer that is above the indicator Sdisplayed immediately previous thereto. In the present embodiment, theindicator S displayed immediately previous is displayed at a higherlevel of transparency than the indicator S displayed later. In otherwords, the indicator S displayed later is displayed at a lower level oftransparency than the indicator

S displayed immediately previous. Accordingly, in the case where aplurality of the indicators S are displayed, the indicator S in theuppermost layer has the lowest level of transparency, and the indicatorS in the lowermost layer has the highest level of transparency.

Furthermore, the indicator S displayed later has a larger size than theindicator S displayed immediately previous thereto. Accordingly, in thecase where a plurality of the indicators S are displayed, the indicatorS in the uppermost layer has the greatest size, and the indicator S inthe lowermost layer has the smallest size. Note that the respectiveindicators S may be set having different sizes but having the sameshape, or may be set so that the sizes are changed by changing one ofthe vertical length and horizontal length of the indicators S.

This display is repeated by the notification image output unit 16. Inthe present embodiment, the indicator S is synthesized with the targetcaptured image, which corresponds to the narrow view region N, and isdisplayed in the monitor 50, as shown in FIG. 2( c). Accordingly, thesynthesized image generation unit 18 generates a synthesized image inwhich the indicator S has been synthesized with the target capturedimage. Through this, an image such as that shown in FIG. 2( c) isgenerated.

Displaying the indicators S in this manner makes it possible for theindicators S to become progressively larger in the display. Throughthis, an occupant of the vehicle 1 can be visually notified that theobject 7 is approaching the vehicle 1.

Furthermore, in the case where the movement direction determination unit15 has determined that the object 7 in the outside region O is movingtoward the center of the target captured image, the notification imageoutput unit 16 sequentially displays a frame indicator W, that has asmaller outer shape than the contour of the target captured image andappears for a set amount of time and then disappears, in differentpositions moving from an outer edge area of the target captured imagetoward the center of the target captured image, and repeats thatdisplay. In the present embodiment, the target captured imagecorresponds to an image of the narrow view region N. Accordingly, in thecase where the object 7 in the outside region O is moving toward thenarrow view region N, the notification image output unit 16 sequentiallydisplays the frame indicator W, that has a smaller outer shape than thecontour of the narrow view region N and appears for a set amount of timeand then disappears, in different positions moving from an outer edgearea of the narrow view region N toward the center of the narrow viewregion N, and repeats that display. As described above, the targetcaptured image, which corresponds to the narrow view region N, isdisplayed in the monitor 50. Accordingly, the frame indicator W having asmaller outer shape than the contour of the narrow view region N refersto the frame indicator W being smaller than the screen size of themonitor 50. Whether or not the object 7 in the outside region O ismoving toward the narrow view region N of the vehicle 1 is determined bythe movement direction determination unit 15, described above.

The “frame indicator W that appears for a set amount of time and thendisappears” refers to a state in which the frame indicator W is notcontinually displayed, but rather in which the frame indicator W isblinking. In the present embodiment, when the frame indicator W isdisplayed, removed, and then once again displayed, the frame indicator Wis displayed in a different position toward the center. Accordingly, theframe indicator W gradually becomes smaller in the display. Thenotification image output unit 16 repeats the movement of the frameindicator W while causing the frame indicator W to blink.

The frame indicator W will now be described. The frame indicator Waccording to the present embodiment is configured having a smaller outershape than the contour of the target captured image (the narrow viewregion N). As shown in FIG. 2( c), a plurality of frame indicators W aredisplayed in the monitor 50 in the present embodiment. In this case, theframe indicator W displayed later has a smaller size than the frameindicator W displayed immediately previous thereto. Furthermore, theframe indicator W displayed later has a lower level of transparency thanthe frame indicator W displayed immediately previous thereto. This makesit possible to display the frame indicator W as if the frame indicator Wis “jumping out” from the center of the screen. Note that as indicatedin FIG. 2( d), the frame indicator W is stored in the notification imagestorage unit 17.

This display is repeated by the notification image output unit 16. Inthe present embodiment, the frame indicator W is synthesized with thetarget captured image, which corresponds to the narrow view region N,and is displayed in the monitor 50, as shown in FIG. 2( d). Accordingly,the synthesized image generation unit 18 generates a synthesized imagein which the frame indicator W has been synthesized with the targetcaptured image. Through this, an image such as that shown in FIG. 2( c)is generated.

The mask region setting unit 19 sets a mask region M that at leastpartially hides the scene in the periphery of the vehicle 1 shown in thetarget captured image. In the present embodiment, the mask region M isset to an upper area of the screen, or in other words, an upper areawithin the target captured image, as shown in FIG. 2( c). This maskregion M is formed spanning across both sides of the target capturedimage in the horizontal direction. The mask region M is filled with acolor such as black so that the scene above the vehicle 1 cannot beseen. Of course, another color may be used instead.

In the case where the object 7 in the outside region O has advanced intoa region corresponding to the target captured image, or in other words,into the narrow view region N, the action image output unit 30 outputsan image into which a notification indicator is absorbed from the sideof the mask region M on which the object 7 is present. Whether or notthe object 7 in the outside region O has advanced into the narrow viewregion N is determined by the movement direction determination unit 15.The “notification indicator” corresponds to the indicator S displayed inthe monitor 50 in the case where the object 7 has advanced into thenarrow view region N. The “side of the mask region M on which the object7 is present” corresponds to the right-side area of the mask region M inthe case where the object 7 is present in the outside region O on theright side, and corresponds to the left-side area of the mask region Min the case where the object 7 is present in the outside region O on theleft side. The “image into which a notification indicator is absorbed”is an image that causes the indicator S to be absorbed and disappearinto the mask region M. This image is stored in advance in the actionimage storage unit 31.

Here, in the case where the object 7 has advanced into the narrow viewregion N, the object 7 is displayed in an end area of the targetcaptured image. Accordingly, in the case where the object 7 has advancedinto the narrow view region N, causing the indicator S to be absorbedinto the mask region M makes it possible to display the object 7, whichis displayed at the end area of the narrow view region N, without theobject 7 being hidden by the notification indicator. Accordingly, thedriver of the vehicle 1 can be appropriately notified of the presence ofthe object 7.

The action image output unit 30 is configured to change the displaycolor of the mask region M from the position where the notificationindicator is absorbed, as the notification indicator is absorbed intothe mask region M. In other words, in the case where the notificationindicator is absorbed from the right side of the mask region M, an imagethat colors the mask region M from the right side to the left side isoutputted, whereas in the case where the notification indicator isabsorbed from the left side of the mask region M, an image that colorsthe mask region M from the left side to the right side is outputted.Coloring the mask region M in this manner makes it possible to notifythe driver of the vehicle 1 of the side into which the object 7 hasadvanced.

FIG. 3 and FIG. 4 illustrate examples of series of images in which thenotification indicator enters the mask region M and the mask region M iscolored. FIG. 3 illustrates an example in which, in the case where theobject 7 in the outside region O is moving toward the narrow view regionN, the indicator S and the frame indicator W are displayed in anoverlapping manner in the narrow view region N. As shown in FIG. 4( a),when the object 7 advances into the narrow view region N from theoutside region O on the right side, the overlapping of the frameindicator W ends. Furthermore, as shown in FIGS. 4( b) to (e), theindicator S enters into the mask region M so as to be sucked into themask region M on the right side. Along with this, the mask region M isgradually colored from the right side, with the entirety of the maskregion M ultimately being colored (FIG. 4( f)).

Returning to FIG. 1, the mask region emphasis display unit 20 displaysthe mask region M with emphasis in the case where the object 7 in theoutside region O has entered into a region corresponding to the targetcaptured image, or in other words, into the narrow view region N. In thepresent embodiment, “displays with emphasis” refers to a blinkingdisplay. Whether or not the object 7 in the outside region O hasadvanced into the narrow view region N is determined by the movementdirection determination unit 15. The mask region emphasis display unit20 causes the mask region M to blink in response to a result of thedetermination performed by the movement direction determination unit 15.This makes it possible to visually notify the driver of the vehicle 1that the object 7 is present in the narrow view region N.

Meanwhile, the mask region emphasis display unit 20 stops displaying themask region M with emphasis in the case where the object 7 has left theregion corresponding to the target captured image, or in other words,the narrow view region N. Whether or not the object 7 has left thenarrow view region N can also be determined by the movement directiondetermination unit 15. In other words, the movement directiondetermination unit 15 can determine that the object 7 has left thenarrow view region N if the object 7 enters into the outside region Ofrom the side of the outside region O that is located toward the narrowview region N. This determination result is also transferred to the maskregion emphasis display unit 20. In the present embodiment, the “displaywith emphasis” refers to a blinking display. Accordingly, when such adetermination result is transferred, the mask region emphasis displayunit 20 stops the mask region M from blinking. This makes it possible tovisually notify the driver of the vehicle 1 that the object 7 is notpresent in the narrow view region N.

Next, a series of processes through which the obstacle alert device 100displays the synthesized image in which a notification image issuperimposed on the target captured image in the monitor 50 will bedescribed using the schematic diagram shown in FIG. 5. First, thecaptured image obtainment unit 11 obtains the captured image G capturedby the camera 5 of the vehicle 1 (step #1).

Next, the target captured image generation unit 12 generates the centralarea of the obtained captured image G as the target captured image (step#2). Meanwhile, the outside region generation unit 13 generates theareas on both sides of the obtained captured image G in the horizontaldirection as the outside region O (step #3). Whether or not the object 7is present in the outside region O generated in this manner isdetermined by the object presence determination unit 14 (step #4).

When it is determined that the object 7 is present in the outside regionO, the movement direction determination unit 15 determines the movementdirection of the object 7 (step #5). In the case where the object 7 ismoving from the outside region O toward the narrow view region N thatcorresponds to the target captured image, the notification image isoutputted by the notification image output unit 16 (step #6). Thisnotification image is outputted having referred to the notificationimage stored in the notification image storage unit 17.

The synthesized image generation unit 18 generates the synthesized imageby superimposing the notification image outputted in step #6 over thetarget captured image generated in step #2 (step #7). The generatedsynthesized image is then displayed in the monitor 50 (step #8).Displaying the target captured image at a large size in the monitor 50in this manner makes it possible to cause the driver of the vehicle 1 tofocus on the periphery of the vehicle 1, and to clarify the direction inwhich the object 7 is approaching the vehicle 1. This in turn enablesthe driver to understand the state of the periphery of the vehicle 1,and makes it possible to clarify that an obstacle is approaching.

Thus, according to the obstacle alert device 100 of the presentinvention, the driver can be notified of the presence and direction ofthe object 7 approaching the vehicle 1 at the point in time when theapproaching object 7 has entered the captured range, while at the sametime displaying the state of the periphery of the vehicle 1, even if theobject 7 has not yet appeared in the screen of the monitor 50 providedin the vehicle 1. Accordingly, the driver will not fail to see theobject 7 approaching the vehicle 1 even in the case where the monitor 50has a small screen. Furthermore, because the indicator S is displayed inan end area of the screen, it is not difficult for the driver to see thestate of the periphery of the vehicle 1. Accordingly, the driver can benotified of the presence of an obstacle (the object 7) approaching thevehicle 1 without the state of the periphery of the vehicle 1 beingdifficult to see.

Other Embodiments

The above embodiment describes the notification image output unit 16 asgradually increasing the display size of the blinking indicator S as theindicator S moves. However, the scope to which the present invention canbe applied is not intended to be limited thereto. The indicator S can ofcourse be displayed at the same size. Furthermore, it is of coursepossible to display the indicator S at a gradually decreasing displaysize. The driver of the vehicle 1 can be appropriately notified of theobject 7 approaching the vehicle 1 even when such a configuration isemployed.

The above embodiment describes the indicator S displayed immediatelyprevious to an indicator S as having a higher level of transparency thanthe indicator S displayed thereafter. However, the scope to which thepresent invention can be applied is not intended to be limited thereto.For example, it is of course possible to display the indicator Sdisplayed immediately previous at a lower level of transparency than theindicator S displayed thereafter, and possible to display the indicatorS displayed immediately previous at the same level of transparency asthe indicator S displayed thereafter.

In the case where there are a plurality of indicators S, the aboveembodiment describes displaying the plurality of indicators S inpositions where the indicators S partially overlap. However, the scopeto which the present invention can be applied is not intended to belimited thereto. It is possible to employ a configuration in which theindicators S do not overlap with each other in the case where aplurality of indicators S are displayed.

The above embodiment describes the indicator S as being shaped as anarrow whose point protrudes toward the center of the narrow view regionN. However, the scope to which the present invention can be applied isnot intended to be limited thereto. The indicator S can of course beconfigured having a different shape.

The above embodiment describes the action image output unit 30 asoutputting an image into which the notification indicator is absorbedfrom the side of the mask region M on which the object 7 is present inthe case where the object 7 in the outside region O has advanced intothe narrow view region N. However, the scope to which the presentinvention can be applied is not intended to be limited thereto. It isalso possible to employ a configuration in which the notification imageoutput unit 16 stops the output of the indicator S in the case where theobject 7 has advanced into the region corresponding to the targetcaptured image (the narrow view region N), as shown in FIG. 6. Ofcourse, in this case, it is also possible to employ a configuration inwhich the output of the frame indicator W is also stopped. Whether ornot the object 7 has advanced into the narrow view region N isdetermined by the movement direction determination unit 15, describedabove. In the case where the object 7 has advanced into the narrow viewregion N, the object 7 is displayed in an end area of the targetcaptured image. Accordingly, the object 7 displayed in the end area ofthe target captured image is not hidden by the notification image andcan therefore be visually confirmed by the driver of the vehicle 1, evenin the case where the output of the notification image is stopped inthis manner.

The above embodiment describes a case where a plurality of theindicators S and the frame indicators W are displayed within the screen.However, the scope to which the present invention can be applied is notintended to be limited thereto. It is also possible to employ aconfiguration in which one each of the indicator S and the frameindicator W are displayed in the screen, as well as a configuration inwhich only the indicator S is displayed.

The above embodiment describes the determination as to whether or notthe object 7 is present as capable of being performed using a knownimage recognition process, such as pattern matching, for example.However, the scope to which the present invention can be applied is notintended to be limited thereto. It is of course possible to detect theobject 7 using sonar or the like, for example.

The above embodiment describes the target captured image generation unit12 as generating the narrow view region N, which corresponds to acentral area of the captured image G, as the target captured image.However, the scope to which the present invention can be applied is notintended to be limited thereto. For example, in the case where thecaptured image G has been obtained by the camera 5 having a narrow viewangle that corresponds to the narrow view region N, it is of coursepossible to utilize the captured image G as the target captured imageas-is. In this case, it is preferable to determine whether or not theobject 7 is present in the outside region O using sonar detection or thelike, as mentioned above.

INDUSTRIAL APPLICABILITY

The present invention can be applied in obstacle alert devices thatalert occupants in a vehicle of the presence of nearby obstacles.

DESCRIPTION OF REFERENCE SIGNS

1: vehicle

7: object

11: captured image obtainment unit

12: target captured image generation unit

14: object presence determination unit

15: movement direction determination unit

16: notification image output unit

100: obstacle alert device

G: captured image

O: outside region

S: indicator

1. An obstacle alert device comprising: a captured image obtainment unitthat obtains a captured image of a scene of the periphery of a vehicle;a target captured image generation unit that generates a target capturedimage based on the captured image; an object presence determination unitthat determines whether or not an object is present in an outside regionthat is on an outer side of the target captured image; a movementdirection determination unit that determines a movement direction of theobject in the outside region; and a notification image output unit that,in the case where the movement direction determination unit hasdetermined that the object in the outside region is moving toward thecenter of the target captured image, sequentially displays a pluralityof indicators, that appear for a set amount of time and then disappear,in different locations of the target captured image, starting with theside having the outside region in which the object is present and movingtoward the center of the target captured image, and repeats this displaywhile displaying the plurality of indicators in positions where theindicators partially overlap with each other, with the indicatordisplayed later being displayed over the indicator displayed immediatelyprevious thereto at the areas where the indicators overlap.
 2. Theobstacle alert device according to claim 1, wherein the indicatordisplayed later has a larger size than the indicator displayedimmediately previous thereto.
 3. The obstacle alert device according toclaim 2, wherein the indicator displayed later has a lower level oftransparency than the indicator displayed immediately previous thereto.4. The obstacle alert device according to claim 1, wherein the indicatoris configured in an arrow shape whose point protrudes toward the centerof the target captured image.
 5. The obstacle alert device according toclaim 1, wherein the notification image output unit is configured tostop the output of the indicator in the case where the object hasadvanced into a region corresponding to the target captured image.